""" Manage the tags of a repository. """

from datetime import datetime, timedelta
from flask import request, abort

from auth.auth_context import get_authenticated_user
from data.model import DataModelException
from endpoints.api import (resource, nickname, require_repo_read, require_repo_write,
                           RepositoryParamResource, log_action, validate_json_request, path_param,
                           parse_args, query_param, truthy_bool, disallow_for_app_repositories)
from endpoints.api.tag_models_interface import Repository
from endpoints.api.tag_models_pre_oci import pre_oci_model as model
from endpoints.exception import NotFound, InvalidRequest
from endpoints.v2.manifest import _generate_and_store_manifest
from util.names import TAG_ERROR, TAG_REGEX


@resource('/v1/repository/<apirepopath:repository>/tag/')
@path_param('repository', 'The full path of the repository. e.g. namespace/name')
class ListRepositoryTags(RepositoryParamResource):
  """ Resource for listing full repository tag history, alive *and dead*. """

  @require_repo_read
  @disallow_for_app_repositories
  @parse_args()
  @query_param('specificTag', 'Filters the tags to the specific tag.', type=str, default='')
  @query_param('limit', 'Limit to the number of results to return per page. Max 100.', type=int,
               default=50)
  @query_param('page', 'Page index for the results. Default 1.', type=int, default=1)
  @nickname('listRepoTags')
  def get(self, namespace, repository, parsed_args):
    specific_tag = parsed_args.get('specificTag') or None
    page = max(1, parsed_args.get('page', 1))
    limit = min(100, max(1, parsed_args.get('limit', 50)))

    tag_history = model.list_repository_tag_history(namespace_name=namespace,
                                                    repository_name=repository, page=page,
                                                    size=limit, specific_tag=specific_tag)

    if not tag_history:
      raise NotFound()

    return {
      'tags': [tag.to_dict() for tag in tag_history.tags],
      'page': page,
      'has_additional': tag_history.more,
    }


@resource('/v1/repository/<apirepopath:repository>/tag/<tag>')
@path_param('repository', 'The full path of the repository. e.g. namespace/name')
@path_param('tag', 'The name of the tag')
class RepositoryTag(RepositoryParamResource):
  """ Resource for managing repository tags. """
  schemas = {
    'ChangeTag': {
      'type': 'object',
      'description': 'Makes changes to a specific tag',
      'properties': {
        'image': {
          'type': ['string', 'null'],
          'description': '(If specified) Image identifier to which the tag should point',
        },
        'expiration': {
          'type': ['number', 'null'],
          'description': '(If specified) The expiration for the image',
        },
      },
    },
  }

  @require_repo_write
  @disallow_for_app_repositories
  @nickname('changeTag')
  @validate_json_request('ChangeTag')
  def put(self, namespace, repository, tag):
    """ Change which image a tag points to or create a new tag."""

    if not TAG_REGEX.match(tag):
      abort(400, TAG_ERROR)

    repo = model.get_repo(namespace, repository)
    if not repo:
      raise NotFound()

    if 'expiration' in request.get_json():
      expiration = request.get_json().get('expiration')
      expiration_date = None
      if expiration is not None:
       try:
         expiration_date = datetime.utcfromtimestamp(float(expiration))
       except ValueError:
         abort(400)

       if expiration_date <= datetime.now():
         abort(400)

      existing_end_ts, ok = model.change_repository_tag_expiration(namespace, repository, tag,
                                                                   expiration_date)
      if ok:
       if not (existing_end_ts is None and expiration_date is None):
         log_action('change_tag_expiration', namespace, {
           'username': get_authenticated_user().username,
           'repo': repository,
           'tag': tag,
           'namespace': namespace,
           'expiration_date': expiration_date,
           'old_expiration_date': existing_end_ts
         }, repo_name=repository)
      else:
        raise InvalidRequest('Could not update tag expiration; Tag has probably changed')

    if 'image' in request.get_json():
      image_id = request.get_json()['image']
      image = model.get_repository_image(namespace, repository, image_id)
      if image is None:
        raise NotFound()

      original_image_id = model.get_repo_tag_image(repo, tag)
      model.create_or_update_tag(namespace, repository, tag, image_id)

      username = get_authenticated_user().username
      log_action('move_tag' if original_image_id else 'create_tag', namespace, {
        'username': username,
        'repo': repository,
        'tag': tag,
        'namespace': namespace,
        'image': image_id,
        'original_image': original_image_id
      }, repo_name=repository)
      _generate_and_store_manifest(namespace, repository, tag)

    return 'Updated', 201

  @require_repo_write
  @disallow_for_app_repositories
  @nickname('deleteFullTag')
  def delete(self, namespace, repository, tag):
    """ Delete the specified repository tag. """
    model.delete_tag(namespace, repository, tag)

    username = get_authenticated_user().username
    log_action('delete_tag', namespace,
               {'username': username,
                'repo': repository,
                'namespace': namespace,
                'tag': tag}, repo_name=repository)

    return '', 204


@resource('/v1/repository/<apirepopath:repository>/tag/<tag>/images')
@path_param('repository', 'The full path of the repository. e.g. namespace/name')
@path_param('tag', 'The name of the tag')
class RepositoryTagImages(RepositoryParamResource):
  """ Resource for listing the images in a specific repository tag. """

  @require_repo_read
  @nickname('listTagImages')
  @disallow_for_app_repositories
  @parse_args()
  @query_param('owned', 'If specified, only images wholely owned by this tag are returned.',
               type=truthy_bool, default=False)
  def get(self, namespace, repository, tag, parsed_args):
    """ List the images for the specified repository tag. """
    try:
      tag_image = model.get_repo_tag_image(
        Repository(namespace_name=namespace, repository_name=repository), tag)
    except DataModelException:
      raise NotFound()

    if tag_image is None:
      raise NotFound()

    # Find all the parent images for the tag.
    parent_images = model.get_parent_images(namespace, repository, tag_image.docker_image_id)
    all_images = [tag_image] + list(parent_images)
    image_map = {image.docker_image_id: image for image in all_images}
    skip_set = set()

    # Filter the images returned to those not found in the ancestry of any of the other tags in
    # the repository.
    if parsed_args['owned']:
      all_tags = model.list_repository_tags(namespace, repository)
      for current_tag in all_tags:
        if current_tag.name == tag:
          continue

        skip_set.add(current_tag.image.ancestor_id)
        skip_set = skip_set | set(current_tag.image.ancestor_id_list)

    return {
      'images': [
        image.to_dict(image_map) for image in all_images
        if not parsed_args['owned'] or (image.ancestor_id not in skip_set)
      ]
    }


@resource('/v1/repository/<apirepopath:repository>/tag/<tag>/restore')
@path_param('repository', 'The full path of the repository. e.g. namespace/name')
@path_param('tag', 'The name of the tag')
class RestoreTag(RepositoryParamResource):
  """ Resource for restoring a repository tag back to a previous image. """
  schemas = {
    'RestoreTag': {
      'type': 'object',
      'description': 'Restores a tag to a specific image',
      'required': ['image',],
      'properties': {
        'image': {
          'type': 'string',
          'description': 'Image identifier to which the tag should point',
        },
        'manifest_digest': {
          'type': 'string',
          'description': 'If specified, the manifest digest that should be used',
        },
      },
    },
  }

  @require_repo_write
  @disallow_for_app_repositories
  @nickname('restoreTag')
  @validate_json_request('RestoreTag')
  def post(self, namespace, repository, tag):
    """ Restores a repository tag back to a previous image in the repository. """

    # Restore the tag back to the previous image.
    image_id = request.get_json()['image']
    manifest_digest = request.get_json().get('manifest_digest', None)

    # Data for logging the reversion/restoration.
    username = get_authenticated_user().username
    log_data = {
      'username': username,
      'repo': repository,
      'tag': tag,
      'image': image_id,
    }
    repo = Repository(namespace, repository)
    if manifest_digest is not None:
      existing_image = model.restore_tag_to_manifest(repo, tag, manifest_digest)
    else:
      existing_image = model.restore_tag_to_image(repo, tag, image_id)
      _generate_and_store_manifest(namespace, repository, tag)

    if existing_image is not None:
      log_data['original_image'] = existing_image.docker_image_id

    log_action('revert_tag', namespace, log_data, repo_name=repository)

    return {
      'image_id': image_id,
      'original_image_id': existing_image.docker_image_id if existing_image else None,
    }